Unmanned drones head into hurricanes' core to get data

Government scientists believe a fleet of small unmanned airplanes sent to hurricanes' cores could lead to revolutionary advances in storm forecasting and measurement.

The drones are able to fly far lower than manned hurricane hunter planes and can beam back information from close to the ocean's surface, where conditions fuel a storm's intensity.

The National Oceanic and Atmospheric Administration began launching drones in 2005, and they've proved so durable and effective that they've been called pioneering.

"It's going to be a revolution in earth system monitoring,'' said Marty Ralph, who heads NOAA's unmanned aircraft efforts. "Like the development of satellites in the 60s and 70s and of weather radar in the 30s and 40s, both of which are fundamental elements of our weather measurement and prediction, it's in the same class.''

Until now, scientists relied solely on hurricane hunters that typically fly at 10,000 feet, though sometimes as low as 5,000 feet, and drop measuring instruments to the ocean. The instruments transmit somewhat random data from points on their way from the plane to the sea, but are unable to provide consistent readings from points close to the water's surface.

The drones fly as low as 300 feet and can go more than 2,000 miles without refueling. The probes on board are not as high-frequency as those on manned flights, but because of their consistent readings from a low altitude, they've been able to give scientists valuable data they've never before been able to gather.

Measures of pressure, temperature, winds and humidity can be beamed back to the National Hurricane Center frequently to help meteorologists better determine a storm's strength.

"This will give the hurricane center what it wants most,'' said Joseph Cione, a lead scientist on NOAA's drone project. "And it will help researchers understand better the interaction between the ocean and the atmosphere.''

Scientists don't envision the drones will replace manned flights. They say they can work in tandem to help plot the most crucial spots in a storm. Within a few years, Ralph said, he expects drones to be dispatched in every storm, a move scientists hope will vastly improve the understanding of how the ocean's temperature intensifies and weakens storms.

NOAA is currently using Australian-made Aerosonde Mark 3 planes weighing about 28 pounds and with a 9-foot wingspan. The 1.6-horsepower engine propels it forward at 60 mph, but it benefits from strong tail winds. In Hurricane Ophelia in September 2005, it reached speeds of 150 mph.

The drone has no wheels. It takes off atop an SUV that releases the plane when it reaches about 50 mph. It lands on its belly, preferably on a grassy area.

In test missions in Hurricane Noel last year and during Ophelia, the Aerosonde came back in good condition. Scientists concede they'll eventually lose one of the roughly $50,000 planes, but it may be a conscious choice to keep it out longer to gather crucial data to save lives.

The drones are also being used beyond the realm of tropical storms. NOAA has completed or planned drone missions examine low-level jet streams that affect West Coast weather; to gather data about pollution over the Indian Ocean; to study the rapid melting of ice on the North Slope of Alaska and its effect on seals there; to monitor whale migration; and to mitigate illegal fishing in the Northwestern Hawaiian Islands.